1. Field of the Invention
The present invention relates to an imaging device, and more particularly, to an imaging device that can acquire a wide-angle image and a telephoto image at the same time.
2. Description of the Related Art
In recent years, an imaging device has been known which can acquire a wide-angle image and a telephoto image at the same time. For example, JP1998-48701A (JP-H10-48701A) discloses an imaging device comprising a wide-angle lens, a telephoto lens, an imaging element (first image sensor) that captures a wide-angle image through the wide-angle lens, and an imaging element (second image sensor) that captures a telephoto image through the telephoto lens. JP2003-116029A discloses an imaging device in which an imaging surface of an imaging element (image sensor) is divided into two regions, a wide-angle image is captured by one region of the imaging surface through a wide-angle lens, and a telephoto image is captured by the other region of the imaging surface through a telephoto lens.
In the imaging device disclosed in JP1998-48701A (JP-H10-48701A), since a wide-angle image and a telephoto image are captured by different image sensors, two image sensors are required. In addition, in the imaging device disclosed in JP1998-48701A (JP-H1048701A), the optical axis of the telephoto lens is shifted such that the wide-angle lens and the telephoto lens are located at different positions, in order to correct the parallax between the wide-angle image captured by the wide-angle lens and the telephoto image captured by the telephoto lens. Therefore, it is difficult to reduce the size and cost of the imaging device. In the imaging device disclosed in JP2003-116029A, the imaging surface of the image sensor is divided into two regions and a wide-angle image and a telephoto image are captured by the two regions. Therefore, it is necessary to increase the size of the image sensor and images are substantially captured by two image sensors. As a result, it is difficult to reduce the size and cost of the imaging device disclosed in JP2003-116029A.
JP2013-205781A discloses an imaging device including an imaging lens that has a plurality of regions (for example, a far focal distance region and a near focal distance region) with different focal lengths or focal distances and an imaging element (directional sensor) that pupil-divides light beams which have passed through the far focal distance region and the near focal distance region, selectively receives the light beams, and captures images. The imaging lens includes a central optical system (wide-angle lens) and an annular optical system (telephoto lens) provided in the periphery of the central optical system which are disposed on the same optical axis (see paragraph 0038 in JP2013-205781A). The imaging device disclosed in JP2013-205781A can pupil-divide light beams which have passed through different regions of the imaging lens and can simultaneously capture a plurality of images (a wide-angle image and a telephoto image) corresponding to the pupil-divided light beams using one image sensor (directional sensor). Therefore, it is possible to reduce the size and cost of the imaging device.